Phase Transition of a Chiral Lead‐Free Hybrid Antimony(III) Halide Crystal

Abstract Chiral organic–inorganic hybrid lead halides have recently attracted great attention due to their unique chirality and diverse functional properties. However, they suffer from highly toxic lead, while lead‐free chiral hybrid metal halides especially those with phase transitions remain sparse. Here, we report a new lead‐free chiral metal halide crystal [ R ‐3‐fluoropiperidinium] 2 SbCl 5 ([ R ‐3‐FPP] 2 SbCl 5 ), which crystalizes in chiral P 2 1 2 1 2 1 space group at 293 K and consists of chiral [3‐FPP] + cations and one‐dimensional [SbCl 5 ] n 2− zigzag chains of corner‐sharing SbCl 6 octahedrons. Notably, [ R ‐3‐FPP] 2 SbCl 5 undergoes an above room temperature phase transition at 313 K, which can be attributed to the order‐disorder transition of both the organic [ R ‐3‐FPP] + cation and inorganic [SbCl 5 ] 2− anions. In addition, [ R ‐3‐FPP] 2 SbCl 5 also shows a broad band gap of 3.21 eV. This work promotes the exploration of chiral lead‐free hybrid lead halides with phase transitions.